The Senate approved a bipartisan federal budget Wednesday that could lead to two rare years of fiscal stability for a government that’s lurched from showdown to showdown for two years.

The modest plan largely maintains the status quo, doing nothing to reduce the national debt or curb the growth of Medicare, Social Security or other entitlement programs that drive budget deficits.

Nor does it guarantee the government will not shut down again early next year, though that prospect now appears highly unlikely. The agreement sets spending levels, and it’s now up to appropriations committees to fill in details of how the money will be spent.

The Senate approved the budget 64-36, with all 53 Democrats voting yes along with two independents and nine Republicans. President Barack Obama is expected to sign the bill, passed overwhelmingly by the House of Representatives last week.

“For the first time in years, both parties in both houses of Congress have come together to pass a budget,” Obama said in a statement. “It’s a good first step away from the shortsighted, crisis-driven decision-making that has only served to act as a drag on our economy.”

The small-scale agreement will ease the automatic spending cuts, or sequester, through the end of fiscal 2015. Washington will spend $63 billion more for discretionary programs, or those subject to annual congressional spending adjustments.

Half will be spent on defense, half on domestic items such as education, transportation and environmental programs. Discretionary spending will rise to $1.012 trillion this fiscal year _ up from the current level of $986 billion _ and $1.014 trillion next year. Entitlement programs are generally tied to formulas that drive their spending without annual approval by Congress.

The budget deal’s new spending is supposed to be offset with $85 billion in new revenues and other savings, spread over 10 years. Among the biggest revenue-raisers are $12 billion from higher aviation security fees and $12.6 billion in pension changes for military and federal personnel.

Congressional appropriations committees are now figuring precisely how the money will be spent. Once they produce recommendations, probably early next month, Congress will have until Jan. 15 to approve detailed spending plans, or appropriations, that stay within the new budget limits.

That still could be difficult. Rarely in recent years has Congress passed such detailed legislation. Serious differences remain on a host of issues, often involving education, health and human services, defense and regulatory matters.

Key players are confident there will be no shutdown.

“We will meet that deadline,” said Senate Appropriations Committee Chairman Barbara Mikulski, D-Md. “It is going to be tough. It is going to be stringent. But we are going to get the job done.”

The big reason for all this confidence: No one wants more fiscal chaos. Congress’ already low Gallup poll approval ratings slumped to a record low 9 percent in November, the month after a 16-day government shutdown.

Lawmakers realized, said Senate Majority Leader Harry Reid, D-Nev., that “gridlock has got to end, and it is ending.”

This month’s budget debate and votes, though, suggested it could come back quickly. Senate Republicans forced this week’s budget debate to go on for nearly two days, angering Reid.

“Republicans have insisted on wasting 30 hours of the Senate’s time before allowing a final vote on this measure, even though they know it will pass with bipartisan support,” he said.

Republicans were annoyed that Democrats use procedural maneuvers to block any changes to the deal. “All deserved a fair and open hearing, but they were denied,” said Sen. Jeff Sessions of Alabama, the top Republican on the Senate Budget Committee.

Most Republican senators made it clear they saw the agreement as a minimal effort to avoid another shutdown crisis and skirt the sequester’s more harsh cuts. They lamented how the bigger issues of how to tackle the nation’s $17.2 trillion debt, or how to stem the growth in entitlements like Medicare and Social Security, were not addressed.

“We kicked the can down the road one more time and missed the opportunity,” said Sen. Rob Portman, R-Ohio, a former White House budget director under President George W. Bush who voted for the deal. “As we all know, unless we address these fiscal problems, the day of reckoning is coming.”

Democrats complained that the agreement did not address the Dec. 28 expiration of emergency unemployment benefits. No action is now expected before that date.

One of the more immediate aftermaths of the budget deal could come quickly. Senators from both parties were not pleased that the bill reduces cost-of-living adjustments for younger military retirees. Sen. Jeanne Shaheen, D-N.H., is pushing a plan to restore the adjustment, which would save $6 billion, by instead eliminating a tax break for offshore corporations.